Jackson Merrett is one of the few players in Essendon’s "narrow waist". Photo: Getty Images

The radical infusion of temporary top-ups has created an extreme example of the hourglass playing list. Four of the seven players Essendon have signed are over 30 – James Kelly, Mathew Stokes, Mark Jamar and Ryan Crowley – and it's possible that another oldie could yet be added.

Brendon Goddard and Adam Cooney, too, are 30, while key defender James Gwilt – suddenly a leading player, rather than an extra – turns 30 in August. Courtenay Dempsey and Mark Baguley turn 29 this year, and ex-Hawk top-up Jonathan Simpkin is also 28.

The worst part of the mass suspensions is that it has eviscerated Essendon's waist – the 23- to 27-year-olds who have sufficient experience for consistency but haven't found themselves in the physical decay of most (non-Hawthorn) veteran players.

Sam Grimley, the former Hawk who is training with the Bombers and is expected to be signed soon, is a prospective recruit who would redress two holes in the list – he's 25 and can play as a key forward.

As another club's list manager explained, hourglass playing lists tend to happen – no one plans on this outcome – when a club has botched a few drafts over a three to four-year period. St Kilda, for instance, are still dealing with the consequences of having had a "busty" team of veterans and skinny waist, where the likes of Jack Steven and David Armitage have been the exceptions in the right age group. Gradually, the Saints are becoming younger.

Geelong's premiership team of 2007, conversely, had a massive waist – the majority of the elite players were in the 23 to 27 age bracket. Hawthorn's three-peat dynasty was significantly older, and this experience, obviously, has been crucial to the sustainability.

The prevailing view among other clubs is that Essendon had little choice but to pursue the "dad's army" brigade as top-ups, given the rules and circumstances.

There was no point, as one list manager explained, in recruiting delisted youngsters when a) the club wants to be competitive and b) Essendon have no hold on the younger player if he performs well – top-ups will be back in the draft.

The waist is thin when one considers not only sheer numbers of mid-20s players, but also their skinny resumes compared with Hurley, Heppell et al.

Craig Bird might have been the proverbial "steak knives" thrown in to facilitate the Jake Carlisle deal, but at 26 and with a strong midfield body, the former Swan shapes as a suddenly important import; he is the right age and will be vaulted into the front line of a midfield that has lost the majority of its experienced A team.

Jackson Merrett, Shaun McKernan and Patrick Ambrose are among the few in the narrow waist.

The Dons don't have to recruit any further top-ups, though they have little to lose – besides more money – by taking the full 10 they're allowed. It will be an expensive exercise, but a worthwhile one: the experience from the veterans – who have something to prove – gives them some prospect of being quasi-competitive.